//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 3.0 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  Copyright 2004, The University of Texas at Austin
//  Dagoberto Salazar - gAGE ( http://www.gage.es ). 2008, 2011
//
//============================================================================

//============================================================================
//
//This software developed by Applied Research Laboratories at the University of
//Texas at Austin, under contract to an agency or agencies within the U.S.
//Department of Defense. The U.S. Government retains all rights to use,
//duplicate, distribute, disclose, or release this software.
//
//Pursuant to DoD Directive 523024
//
// DISTRIBUTION STATEMENT A: This software has been approved for public
//                           release, distribution is unlimited.
//
//=============================================================================

/**
 * @file Decimate.hpp
 * This class decimates GNSS Data Structures data given a sampling interval,
 * a tolerance, and a starting epoch.
 */
#ifndef GPSTK_DECIMATE_HPP
#define GPSTK_DECIMATE_HPP

#include "../gpstk/Exception.hpp"
#include "../gpstk/ProcessingClass.hpp"



namespace gpstk
{

/// Thrown when some epoch data must be decimated
/// @ingroup exceptiongroup
NEW_EXCEPTION_CLASS(DecimateEpoch, gpstk::Exception);


/** @addtogroup DataStructures */
//@{


/** This class decimates GNSS Data Structures data.
 *
 * This class is meant to be used with the GNSS data structures objects
 * found in "DataStructures" class.
 *
 * A typical way to use this class follows:
 *
 * @code
 *      // INITIALIZATION PART
 *
 *      // EBRE station nominal position
 *   Position nominalPos(4833520.192, 41537.1043, 4147461.560);
 *   RinexObsStream rin("ebre0300.02o");  // Data stream
 *
 *      // Load all the SP3 ephemerides files
 *   SP3EphemerisStore SP3EphList;
 *   SP3EphList.loadFile("igs11512.sp3");
 *   SP3EphList.loadFile("igs11513.sp3");
 *   SP3EphList.loadFile("igs11514.sp3");
 *
 *      // Set up Niell tropospheric model
 *   NeillTropModel neillTM( nominalPos.getAltitude(),
 *                           nominalPos.getGeodeticLatitude(),
 *                           30 );
 *
 *      // Objects to compute the model
 *   BasicModel basicM(nominalPos, SP3EphList);
 *   ComputeTropModel computeTropo(neillTM);
 *
 *      // More declarations here: ComputeMOPSWeights, SimpleFilter,
 *      // LICSDetector, MWCSDetector, SolidTides, OceanLoading,
 *      // PoleTides, CorrectObservables, ComputeWindUp, ComputeLinear,
 *      // LinearCombinations, etc.
 *
 *      // Declare a SolverPPP object
 *   SolverPPP pppSolver;
 *
 *      // Object to decimate data: Take data each 900 s, tolerance 5 s
 *   Decimate decimateData( 900.0,
 *                          5.0,
 *                          SP3EphList.getInitialTime() );
 *
 *     // PROCESSING PART
 *
 *   gnssRinex gRin;
 *
 *   while(rin >> gRin)
 *   {
 *      try
 *      {
 *         gRin  >> basicM
 *               >> correctObs
 *               >> compWindup
 *               >> computeTropo
 *               >> linear
 *               >> pcFilter
 *               >> markCSLI
 *               >> markCSMW
 *               >> decimateData   // Continue processing only each 900 s
 *               >> mopsWeights
 *               >> pppSolver;
 *      }
 *      catch(DecimateEpoch& d)
 *      {
 *            // If we catch a DecimateEpoch exception, just continue
 *            // with the next epoch.
 *         continue;
 *      }
 *      catch(...)
 *      {
 *         cerr << "Unknown exception at epoch: " << time << endl;
 *         continue;
 *      }
 *
 *         // Print results
 *      cout << time.DOYsecond()      << "  "; // Output field #1
 *      cout << pppSolver.solution[1] << "  "; // dx: Output field #2
 *      cout << pppSolver.solution[2] << "  "; // dy: Output field #3
 *      cout << pppSolver.solution[3] << "  "; // dz: Output field #4
 *      cout << pppSolver.solution[0] << "  "; // wetMap: Output field #5
 *      cout << endl;
 *   }
 * @endcode
 *
 * Each Decimate object has a sampling interval, a tolerance and a epoch
 * to start decimation. If decimation conditions are met, it returns the
 * incoming GNSS Data Structure without changes and the processing chain
 * continues.
 *
 * Otherwise, it will stop the processing chain and throw a
 * "DecimateEpoch" exception. The program then must handle it
 * appropriately, usually just issuing a 'continue' statement in order
 * to process next epoch.
 *
 * @sa Synchronize.hpp for another time management class.
 *
 */
class Decimate : public ProcessingClass
{
public:

    /// Default constructor
    Decimate()
        : sampling(30.0), tolerance(0.5),
          lastEpoch(CommonTime::BEGINNING_OF_TIME)
    { };


    /** Common constructor.
     *
     * @param sampleInterval      Sampling interval, in seconds.
     * @param tol                 Tolerance, in seconds.
     * @param initialEpoch        Epoch to start decimation.
     */
    Decimate( const double sampleInterval,
              const double tol,
              const CommonTime& initialEpoch )
        : sampling(sampleInterval), tolerance(tol), lastEpoch(initialEpoch)
    { };


    /** Returns a satTypeValueMap object, adding the new data generated
     *  when calling this object.
     *
     * @param time      Epoch corresponding to the data.
     * @param gData     Data object holding the data.
     */
    virtual satTypeValueMap& Process( const CommonTime& time,
                                      satTypeValueMap& gData )
    throw(DecimateEpoch);


    /** Returns a gnnsSatTypeValue object, adding the new data
     *  generated when calling this object.
     *
     * @param gData    Data object holding the data.
     */
    virtual gnssSatTypeValue& Process(gnssSatTypeValue& gData)
    throw(DecimateEpoch)
    {
        Process(gData.header.epoch, gData.body);
        return gData;
    };


    /** Returns a gnnsRinex object, adding the new data generated
     *  when calling this object.
     *
     * @param gData    Data object holding the data.
     */
    virtual gnssRinex& Process(gnssRinex& gData)
    throw(DecimateEpoch)
    {
        Process(gData.header.epoch, gData.body);
        return gData;
    };


    /// Returns sampling interval, in seconds.
    virtual double getSampleInterval(void) const
    {
        return sampling;
    };


    /** Sets sampling interval.
     *
     * @param sampleInterval      Sampling interval, in seconds.
     */
    virtual Decimate& setSampleInterval(const double sampleInterval);


    /// Returns tolerance, in seconds.
    virtual double getTolerance(void) const
    {
        return tolerance;
    };


    /** Sets tolerance, in seconds.
     *
     * @param tol                 Tolerance, in seconds.
     */
    virtual Decimate& setTolerance(const double tol);


    /** Sets epoch to start decimation.
     *
     * @param initialEpoch        Epoch to start decimation.
     */
    virtual Decimate& setInitialEpoch(const CommonTime& initialEpoch)
    {
        lastEpoch = initialEpoch;
        return (*this);
    };


    /// Returns a string identifying this object.
    virtual std::string getClassName(void) const;


    /// Destructor
    virtual ~Decimate() {};


private:


    /// Sampling interval, in seconds
    double sampling;

    /// Tolerance, in seconds
    double tolerance;

    /// Last processed epoch
    CommonTime lastEpoch;

}; // End of class 'Decimate'

//@}

}  // End of namespace gpstk

#endif   // GPSTK_DECIMATE_HPP
